The only problem you'll be facing with basement A/C units is that they take up quite a lot of storage space. But it's just a slight inconvenience if you'll think about all the expense and other damage that could possible come from leaks when you install a roof A/C

Had experience with both. Like what everyone said, roof a/c units are more prone to cause leaks but they are rather quiet. Basement a/c units are really efficient when it comes to keeping the coach really cool and on saving on LP when you're plugged into either a 50amp or 30 amp hookup. The downside to them is that they are relatively noisier than roof a/c units. It can take some time to get used to the noise especially when you sleep since the units are usually located underneath the bedroom. Personally, I find the humming noise rather relaxing so I'm not really bothered by it.